A blower apparatus of certain kind hitherto known is equipped with centrifugal blower units disposed in parallel to one another and retained by a position restricting member (Patent literature 1, for example).
Referring now to the accompanying drawing, description is provided hereafter of the blower apparatus. FIG. 7 is a plan view showing a structure of the conventional blower apparatus.
As shown in FIG. 7, main frame 101 comprises two pairs of mutually confronted side plates 102, a top plate (not shown) and a bottom plate (not shown). One of side plates 102 is provided with main-frame inlet port 104 for connection with inlet side duct 103, and another of side plates 102 is provided with main-frame outlet port 106 for connection with outlet side duct 105.
A space inside main frame 101 between side plate 102 having main-frame inlet port 104 and another side plate 102 having main-frame outlet port 106 is separated by partition plate 108 provided with openings 107. There are two centrifugal blower units 111 placed in parallel and fixed between partition plate 108 and position restricting member 109 installed on one side of partition plate 108 near side plate 102 having main-frame inlet port 104. Two centrifugal blower units 111 are fixed with their air outlets 110 aligned with openings 107 of partition plate 108.
These centrifugal blower units 111 can be removed one after another from the front side by disengaging position restricting member 109 through maintenance opening 112 provided in one of side plates 102 of main frame 101.
In the conventional blower apparatus of this type, centrifugal blower units 111 can be removed one after another from the front side by disengaging position restricting member 109 through maintenance opening 112 provided in one of side plates 102 of main frame 101. It is necessary, however, that both of these centrifugal blower units 111 are to be removed one by one from the front side even when only one of centrifugal blower units 111 located at the far backside of main frame 101 needs to be checked, because of the structure that two centrifugal blower units 111 are placed in parallel to each other between partition plate 108 and position restricting member 109. The above structure thus has a drawback of requiring an extra time and effort in order to remove both of centrifugal blower units 111.    Patent Literature 1: Japanese Utility Model Unexamined Publication, No. 1986-127335